III-V nitrides and performance of graphene on copper plasmonic biosensor

In the present study, the influence of iii-v nitrides as well as Ge and Si on the sensitivity and performance of a graphene protected copper plasmonic biosensor has been investigated. These semiconductors have been used between copper (Cu) and graphene layers on a SF 10 glass prism. The sensitivity and performance of the biosensor has been computed for with and without semiconductors. III-V nitrides demonstrated high sensitivity and high figure of merit (FOM) in comparison to Si and Ge due to their superior electronic and optical properties. The enhancement of evanescent electric field due to Si, Ge, AlN, GaN and InN have been computed and found highest enhancement for InN. This happens due to high refractive index of InN than other semiconductors. Analysis shows that for a high sensitive imaging biosensor the required optimal thickness of copper, InN and graphene are respectively 32 nm, 13 nm and 0.34 nm for light of wavelength λ = 633 nm (red HeNe laser). This study suggests that InN would be a better choice for fabrication of new imaging plasmonic biosensors for chemical and biological sensing. •Effect of semiconductors on performance of a graphene plasmonic biosensor has been explored.•Figure of merit (FOM) of sensor has been computed.•III-V nitride shows higher FOM than Si and Ge.•Highest field enhancement is achieved for InN.•III-V nitrides improve overall performance of graphene on copper plasmonic biosensor.